PackedQuadPrefixTree in a geo context indexes a point at longitude +180 under the -180 edge cell, but point queries look in the +180 edge cell, so RPT and CompositeSpatialStrategy Intersects/Contains with that same point miss the document

Finding LFV-705Area: spatial-extras / prefix trees: PackedQuadPrefixTree point-to-cell lookup (RecursivePrefixTreeStrategy and CompositeSpatialStrategy point queries)Priority: lowImpact: silent wrong resultsNovelty: new

Finding page for LFV-705

AI-assisted finding, confirmed by automated checks, not yet triaged by a human Lucene committer. This site files nothing upstream.

What it shows

You index a point at longitude +180, for example Pt(180, 10), with RecursivePrefixTreeStrategy over PackedQuadPrefixTree(SpatialContext.GEO, 8) and query Intersects or Contains with that same point; the document must match, since a point intersects and contains itself and the prefix-tree approximation may only add matches (SpatialArgs: the error 'should not shrink' the shape). Instead the query returns 0 hits, and so does CompositeSpatialStrategy's Intersects: indexing keeps the first cell in Z order whose rectangle relate()s to the point, and a geo rectangle treats +180 as -180, so the point is stored in the cells at the -180 edge, while the point query's cell lookup (PackedQuadPrefixTree.getCell, a mid-point walk since LUCENE-8755 in 8.3.0) sends x=+180 to the cells at the +180 edge. The same point at -180, QuadPrefixTree, and a rectangle query touching +180 still find the document.

The test shows that a document indexed at longitude +180 with RecursivePrefixTreeStrategy over PackedQuadPrefixTree(SpatialContext.GEO, 8) is not found by an Intersects query with that same point (indexing stores it in the -180 edge cell, the point query looks in the +180 edge cell).

Expected vs actual

Expected 1 hit (a point intersects itself); actual 0 (expected:<1> but was:<0>), with -ea and -da.

Files

Run it

# Lucene checkout at the tested commit, built with: ./gradlew --no-daemon assemble   (JDK 25)
LUCENE=/path/to/lucene; V=12.0.0-SNAPSHOT
CP=$LUCENE/lucene/core/build/libs/lucene-core-$V.jar
CP=$CP:$LUCENE/lucene/codecs/build/libs/lucene-codecs-$V.jar
CP=$CP:$LUCENE/lucene/test-framework/build/libs/lucene-test-framework-$V.jar
CP=$CP:$LUCENE/lucene/spatial-extras/build/libs/lucene-spatial-extras-$V.jar
CP=$CP:$LUCENE/lucene/spatial3d/build/libs/lucene-spatial3d-$V.jar
CP=$CP:randomizedtesting-runner-2.9.2.jar:junit-4.13.2.jar:hamcrest-3.0.jar   # test-framework dependencies (Maven Central)
CP=$CP:junit-platform-console-standalone-6.1.3.jar   # JUnit Platform console launcher (Maven Central)

javac -d classes -cp "$CP" $(find src -name '*.java')

# run 1: assertions on, seed DEADBEEF
java -ea -esa --add-modules jdk.incubator.vector --enable-native-access=ALL-UNNAMED -Dtests.seed=DEADBEEF \
     -cp "classes:$CP" org.junit.platform.console.ConsoleLauncher \
     execute --select-class org.apache.lucene.spatial.prefix.TestPackedQuadPlus180Point

The module(s) spatial-extras also need their third-party runtime jars; ./gradlew -p lucene/<module> dependencies lists them.

Gradle alternative: copy the test into the matching module's src/test/ tree of the checkout and run ./gradlew -p lucene/<module> test --tests <class> -Ptests.seed=<seed> (add -Ptests.asserts=false for a run without assertions).

Formal models and scripts this finding's part of the hunt used: spatial-extras-composite-and-prefix-tree-query-cross-check

Feedback

Open an issue in lucene-ai-bug-hunt. Please do not open issues or pull requests in apache/lucene about this finding unless a Lucene committer agrees it should be filed.

Snapshot of 2026-11-04. AI-assisted; not yet triaged by a human Lucene committer. Feedback: open an issue in lucene-ai-bug-hunt.